/*
 * @author 707<707472783@qq.com>
 * This program uses pointer parameters exchange two value.
 */
#include <iostream>
using std::cout;
using std::endl;
void exchange(int *pi1, int *pi2)
{
    *pi2 = *pi1 + *pi2 - (*pi1 = *pi2);
}
int main()
{
    int i1 = 7;
    int i2 = 0;
    exchange(&i1, &i2);
    cout << i1 << " " << i2 << endl;
    return 0;
}
